How often should you expect to replace the cell in a salt water pool chlorinator?

From what I have seen and heard it's about 1 to 3 years depending on how well you take care of it. At my home It's going on three years and going strong. Every 2 to 3 weeks I check the cell and clean it if needed. The first cell I had went bad after 9 months. It was replaced under warranty. They said that batch had a defect. Since then it has been great. I use an autopilot digital 36.